Method of preparing semiconductor material

Claim 1

A METHOD OF PREPARING SILICON MATERIAL FOR SEMICONDUCTOR DEVICES COMPRISING THE STEPS OF PLACING A PIECE OF SILICON MATERIAL CONTAINING AN N-TYPE IMPURITY INTO A CONCENTRATED SOLUTION OF BORIC ACID AT A TEMPERATURE OF 90-100*C. FOR A PERIOD OF TIME UNTIL THE TEMPERATURE OF SAID PIECE IS APPROXIMATELY TOO THAT OF THE SOLUTION; WITHDRAWING SAID SILICON MATERIAL FROM THE SAID SOLUTION AT A RATE WHEREBY AN EVEN FILM OF SAID BORIC ACID IS DEPOSITED ON THE SURFACE OF SAID SEMI-CONDUCTOR MATERIAL; HEATING SAID MATERIAL AT APPROXIMATELY 1300*C. TO DIFFUSE BORON FROM SAID BORIC ACID INTO A PORTION OF SAID SILICON PIECE FOR FORMING A P-TYPE IMPURITY REGION AND TO DEPOSIT A LAYER OF GLASS-LIKE NON-METALLIC MASKING MATERIAL CONTAINING AT LEAST BORON, SILICON AND OXYGEN ON THE SURFACE OF SAID SILICON PIECE; REMOVING A PORTION OF SAID MASKING MATERIAL AND A PORTION OF SAID P-TYPE IMPURITY REGION TO EXPOSE A PORTION OF SAID N-TYPE SILICON PIECE; AND DIFFUSING AN N-TYPE IMPURITY INTO SAID EXPOSED N REGION OF SAID PIECE AT A TEMPERATURE OF APPROXIMATELY 1200*C. TO FORM AN N+ REGION, WHEREBY A PIECE OSF SILICON MATERIAL HAVING A P-N-N+ CONFIGURATION IS OBTAINED.